test_override_raises_on_both_system_prompt_and_system_message() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/core/test_overrides.py lines 208–228

    def test_override_raises_on_both_system_prompt_and_system_message(self) -> None:
        """Test that `ValueError` is raised when both prompt params are provided."""
        model = GenericFakeChatModel(messages=iter([AIMessage(content="Hello")]))
        request = ModelRequest(
            model=model,
            system_message=None,
            messages=[HumanMessage("Hi")],
            tool_choice=None,
            tools=[],
            response_format=None,
            state=AgentState(messages=[]),
            runtime=None,
        )

        with pytest.raises(
            ValueError, match="Cannot specify both system_prompt and system_message"
        ):
            request.override(
                system_prompt="prompt",  # type: ignore[call-arg]
                system_message=SystemMessage("message"),
            )